Vehicle suspension



March l2, 1946. A. s. KRoTz 2,396,579

VEHICLE SUSPENSION Filed Jan. 8, 1942 2 sheets-shea 1 za /s E I' y March 12, 1946. A. s. KRoTz VEHICLE SUSPENSION Filed J`an. 8, 1942 2 Sheets-Sheet 2 Patentecl Mar. 12, 1946 2,396,579 VEHICLE SUSPENSION Alvin S. Krotz, Akron, Ohio, assignor to The B. F.

Goodrich Company, New York, N. Y., a corporation of New York Application January 8, 1942, Serial No. 426,057

claims.' (c1. 267-21) 'I-'his invention relates to vehicle suspensions. and especially to suspensions of the throughaxle type for heavy-duty motor vehicles such as trucks and busses, although features of the invention are useful in vehicles o other types, such. for example, as passenger vehicles and rail trucks,

' including vehicles other than the through-axle type. l

Heretofore, in vehicle suspensions for trucks andlbusses, the springs of the vehicle, if sufciently stiff to provide lcushioning under heavy loads, in many cases have been too stiff for cornfortalble springing under lighter loads, or if the springing means have been soft enough at light .loads for comfortable ride, an undesirably large amplitude of springing movement has been required in order to have springing under heavy loads and in some cases cushioning has been prevented altogether.

The chief objects of the present invention are to provide for effective springing of a vehicle through awide range of load conditions, and to provide a suspension having relativelyA soft springing for light loads and stiffer springing tor heavier loads. A further object is to utilize ei fectively in combination the advantages of springs of resilient rubber or other rubber-like material in straight shear and springs of such material in torsion.

Further objects are to provide durability and compactness of structure and to provide for con venience and economy of manufacture.

These and further objects will be apparent from the following description, reference being had tc the accompanying drawings in which:

Fig. 1 is a plan view of a vehicle `suspension constructed in accordance with and embodying the invention, parts being broken away and sectioned.

Fig. 2 is a section taken along the line 2-2 o Fig. l.

Fig. 3 is a section taken along the line 3--3 oi" Fig. l.

In the illustrative embodiment of Figs. l'to 3 of thel drawings a vehicle suspension is shown as applied, for example, to the rear or driving-end ci a heavy-duty truck or passenger bus of the dual rear wheel type. The construction comprises a pair of springs l, I@ mounted on an axle Il of the through-axle type and having a relatively soft springing for cushioning the vehicle when empty or under light loads, and relativelysti? springing means, such asa torsion spring l2 secured to the frame or body of the vehicle, for cushioning the vehicle under heavy loads, the

torsion spring I2 being'cnnected with the softer springs I0, I0 by swinging arm members I3. I3'. Dual wheels Il, I4 are shown mounted on an end of the axle I i.

The relatively soit springs II)I I0 may comprise any suitable spring construction, but each of these springs preferably comprises two bodies of resilient rubber or other rubber-like material I5 and I6 mounted between an adapter element II secured to the axle II and a housing structure I8, the rubber-like material It and I6 being disposed in a manner such that deflections of the axle II are resisted by straightshear stresses in the rubber-like material I5 and I6. The housing` structure I8 preferably comprises, for facilitating assembly; two pairs of side-plates I8a, I8a and ib, lsb, secured to projecting ilanges I3a and I 3b of the arm member I3 as by means of bolts l3'c, I3c. Portions of the housing structure I3 encircling the axle I I are spa'ced irom the axle an end-plate 2| on the opposite side of the axle II from the arm member I3. The adapter element I'I is positioned on the axle II, as by means of welded portions 22, 22, or by otherv suitable attaching means. The rubber-like material I5 and yI8 is mounted on mounting-plates I5a, I5a and Ita, ISa, which plates are secured between the adapterelement il and the end face of the arm member I3 and the end-plate 2| in a. manner to provide springing of the vehicle by shear stresses in the bodies of rubber-like material I5 and le.

The rubber-like material I5 and I6 is secured to the plates Ia, Ia and ISa, Ita asby means of a vulcanized bond or by other suitable attech ing means and thecmounting plates IEa, Iia and i511, Ia are attached to the supporting members of the housing structure I8 by any suitable means, such for example, as by dowel pins 23, 23.

The shear springs I0, IIl are preferably mounted on the axle Ii close to the wheels to permit independent -movement of each spring, as in the cases where one wheel is to rise and fall independently of the other through the limited range permitted.

The ends of the armmembers I3, I3 away from the axle Il 'have hanged portions 3B, 30 adapted to receive hub members 3l, 3| and are attached thereto by means of bolts 32, 32er by other suit- 2 able fastening means, the hub members 3|, 3| being adapted to receive the torsion spring I2 in fixed relation, optionally adjustable, with respect; thereto and to hold the same against any possibility of relative rotation with respect to the arm members I3, I3. An inner shell 34 for receiving a body of rubber or other resilient rubber-like material 35 of the torsion bushing I2 is mounted on the outer surface of the hub members 3|, 3| in any suitable manner, as for example, by welding or brazing at the vend of the hub members 3|, 3| as indicated at 36 in Fig. 1 and at the end of the shell member I4 at 3l in Fig. l.

An outer shell member is mounted to encircle the body of rubber-like material 35 and is preferably in two sections 3B, 3B fastened together as by means of bolts 39, 39 at projecting portions 40, 40 of the sections 3B, 38 of the outer shell member. The sections 38, 38 of the circumferentially discontinuous outer shell member permit adjustment of the initial radial compression in the rubber-like material 35 of the torsion bushing I2 by the provision oisuitable spacer members between the projecting portions 40, 40, as desired.

The torsion bushing I2 may be secured to the body and frame of the vehicle by any suitable means, as for example, by heavy bracket members 4I, 4| secured to an arcuate member 42, which arcuate member 42 has projecting portions 43, 43 adapted to be to be secured to the bushing at the projecting portions 40, 40 of the outer shell members 38, 38 by means of the bolts 39, 39. Spacer members may be provided between the projecting portions 43, 43 of the arcuate supporting member 42 and the projecting portions 40, 40 of the outer shell members, 3B on either side of the torsion bushing I2 to permit adjustment of the initial tilt of the bushing when mounted in the vehicle, as desired, and also adjustment in service. A spacer member is shown incorporated in the assembly at u in Figs. 2 and 3. Reinforcing pistes suitably secured to the bracket members 4I 4| as by means of welding are provided to add to the strength and rigidity of the structure. l

Under springing movement of the vehicle axle |I with respect to the body, the shear springs l0, I0, having a. relatively high deflection -for soft springing, provide for cushioning of the vehicle by resisting the relatively small deilectionswhen the initial deflection is slight, as when the vehicle is only lightly loaded. When the vehicle is more heavily loaded, the initial deflection of the axle is relatively large sothat the adapter elements I1, I1 of the shear springs I0, II) are moved into contact with the upper portion of the housing structure I8 of the shear springs III,- I0. Springing deflections of the axle under the relatively greater weight of the loaded vehicle are then resisted and cushioning of the vehicle is provided for by torsional stresses in the resilient material of the torsion bushing I2 which provides stiffer springing as compared to the shear'springs I 0, I0.

Even undel the conditions of the heavier loads. the shear springs III, III are effective to permit dinerential vertical movements of the connected wheels by virtue of the ability of one Wheel to drop with respect to the other. This differential action may be augmented as desired by the designv of the torsion spring I2 such that the shaft is permitted some tilting with respect to the outer housing by virtue of the softness of the rubber, the thickness thereof in relation to its length, or both.

The suspension aflords desirably soft springing of the vehicle under light loads. and stiffer springing under heavy loads, and this is eiected by uti- :,soaave lizing advantageously the combined action of rubber springs in straight shear and rubber springs A 4 of the straight shear spring bodies I5, I6 has not reached its limit.

Resilient bumpers 45, 45 may be provided in the shear springs III, III at the points oi contact of the elements of the springs under heavy loads, al-

though this is not always essential owing to the double cushioning action of the springs III and I2. Variations may be made without departing from the scope of the invention as it is deilned by the following claims.

I claim:

1. A vehicle suspension comprising springing means including relatively stiff torsional springing means of resilient rubber-like material for resisting deflections under heavy loads, a second springing means, and an arm structure for inter-connecting said springing means, said second springing means comprising resilient rubber-like material, relatively soft as compared to the iirst said springing means, mounted for resisting deflections in straight shear under lighter loads, and said arm structure being mounted to transmit springing movement torsionally to said stiff springing means.

2. A' vehicle suspension comprising springing means including relatively stiiI springing means of resilient rubber-like material for resisting deflections under heavy loads by torsional stresses in said rubber-like material, 'a second springing means, a. swinging arm structure for inter-connecting said springing means and imposing torsional stress on said rubber-like material, said second springing means comprising resilient rubber-like material, relatively soft as compared to the first said springing means, for resisting defiections under lighter loads by shear stresses in said rubber-like material, and means for limiting deflection of said second springing means and transmitting further deflection to said arm and the first said springing means.

3. In a vehicle having a 'body and a wheelmounting structure, a suspension comprising relatively soft springing means of resilient rubberlike material mounted at said wheel-mounting structure' for resisting `springing deflections of the wheels under light loads by shear stresses in said rubber-like material, means for limiting the ilexing range of said soit springing means, a second springing means of resilient rubber-like material, relatively stiiI as compared to the first said springing means, disposed between the wheel-mounting structure and the body for resisting springing deflections of the Wheels under heavierloads by torsional stresses in said rubber-like material independently of said first springing means, and an arm structure for connecting said first and second springing means.

4. In a vehicle having a body and a throughaxle, a suspension comprising relatively soft springing means of resilient rubber-like material mounted at said axle for resisting springing deilections of the wheels under light loads by shear stresses in said rubber-like material, means for limiting the exing range of said soft springing means, a second springing means of resilient rubber-like material, relatively stiif'as compared to the first said springing means, between the vaxle and the body for resisting springing deflections of the wheelsunder heavier loads by torsional stresses in said rubber-like material, and an arm structure for connecting said rst and second said springing means.

5. In a vehicle having a body and a throughaxle, a suspension comprising a spring mounted upon the frame including radially spaced-apart inner and outer generally horizontal members, an arm structure extending from one of said members in the fore and aft direction of the vehicle and a. body of resilient rubber-like material be.. tween said members and bonded thereto for resisting vertical swinging movement of said arm by torsional stresses yin said material, said arm structure having a housing enclosing said throughaxle, at least one spring of resilient rubber-like material between said housing and said throughaxle, and secured to both in a 'relation to cushion initial axle deflections bysshear stresses in the material, and means for limiting the relative movement of the through-axle and housing for transmitting'further axle deiiections to said arm structure and rst saidspring, thesecond said spring beingrelatively soft as compared to the rst said spring for cushioning axle deflections under light loads.

ALVIN S. KROTZ. 

